Thesis (M.S. in Physics)--United States Naval Postgraduate School, California. / "Unclassified Instrumentation." Includes bibliographical references (p. 37). 16

The vacuum system of the Van de Graaff generator is described. Techniques in the construction of the high voltage vacuum tubes are indicated. The required performance of the system and the methods of attaining it are outlined, calculations being given in the Appendices. Vacuum pressure gauges are described and the indicated performance of the system recorded. Vacuum protection circuits are discussed. Methods of leak detection are discussed and the University of British Columbia mass spectrometer leak detector described in detail. The theory of analysis by a spectrometer with a coterminous crossed electric and magnetic field is given. An operating procedure for the spectrometer is described in detail and some results recorded and discussed. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

No description available.

The relative abundances of the stable and long-lived Isotopes of rubidium, cesium, strontium, cerium, neodymium, and samarium resulting from the ther­mal neutron fission of U^235 and Pu^239 were determined mass spectrometrically. Special precautions were taken to eliminate or at least minimize contamination of the sub-microgram quantities of fission products with the naturally occurring elements. By using isotope dilution the yields of isotopes of different elements were related with very good precision. Sufficient information was available to evaluate from such results the absolute cumulative yields of twenty-seven mass chains for U^235 fission. It was possible from the results of the present study of make a quantitative comparison between the yields of the heavy fragments for U^235 and Pu^239 fission, with special attention being given to the fine structure supposedly resulting from the influence of nuclear shells involving 50 and 82 neutrons. / Thesis / Master of Science (MS)

An electron multiplier has been developed which has increased the sensitivity of an existing mass spectrometer toy a factor of 10^5. This increased sensitivity has permitted determination of fission yields of substances that have undergone little fission. Two such samples, for which the rare gas isotopes have been analysed, are Bohemian pitchblende and the products resulting from the neutron fission of Th232, The Bohemian ore exhibited more neutron fission than any uranium deposit previously analysed. An explanation of this effect may be obtained by considera­tion of the geological and chemical nature of the deposit. The neutron fission of thorium, which shows fine structure in both the xenon and krypton regions, is similar to the patterns of u235 U235 and pu239, / Thesis / Master of Science (MS)

<p> A description of the McMaster tandem mass spectrometer is given and the usefulness of this instrument in high sensitivity applications is discussed.</p> <p> The pulse characteristics of the 17 stage Allen type electron multiplier which is used on the two stage mass spectrometer were determined and possible means of achieving an improved response in counting applications are discussed.</p> <p> An ion source of the crucible variety was constructed which made possible the detection of 10^-9 grams of a tin isotope. This source was used to detect sub microgram quantities of an enriched tin sample and was also used for the qualitative analysis of a sample which contained tin extracted from a reactor irradiated fuel rod.</p> / Thesis / Master of Science (MSc)

The uploaded file contains both Part 1 and Part 2 of the work. / An abstract is not provided. / Thesis / Master of Science (MSc)

No description available.

This thesis describes a non-magnetic mass spectrometer incorporating the following components: a heated filament source, an electrostatic energy analyser, and a time-of-flight velocity analyser. The last component measures the time required for an ion to go between two small condensers by means of a radio frequency voltage applied to the condensers. If an ion passes successively through both condensers when the field in them is zero, it is collected and detected. It is then possible to relate the e/m to the frequency of the applied voltage when the energy of the ion and the distance between the centres of the condensers is known. Theory is presented which permits the calculation of resolution and current intensities. The values so obtained are realized experimentally. / Thesis / Master of Science (MSc)

A study has been made of the external conversion spectrum of gamma-rays of less than 200 kev. A set of semi-empirical curves relating the photoelectric peak height to the gamma-ray intensity has been established using antimony radiators. These results will be discussed. A method of preparing thin beta sources will also be described. / Thesis / Master of Science (MSc)